class Solution {
    vector<int> path;
    vector<vector<int>> ret;
    bool check[9];
public:
    vector<vector<int>> permuteUnique(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        dfs(nums,0);
        return ret;
    }
    void dfs(vector<int>& nums,int pos)
    {
        if(pos==nums.size())
        {
            ret.push_back(path);
            return;
        }

        for(int i=0;i<nums.size();i++)
        {
            if(check[i]==true
            || (i!=0 && nums[i]==nums[i-1] && check[i-1]==false))
            {
                continue;
            }

            path.push_back(nums[i]);
            check[i]=true;
            dfs(nums,pos+1);
            path.pop_back();
            check[i]=false;
        }
    }
};
